ScaleUp – Large-Scale Underground Tank Thermal Energy Storage as a Key Technology for Sustainable District Heating Systems

The main goal of the ScaleUp project is the decarbonization of district heating systems. In addition, ScaleUp aims to increase the acceptance of such innovative structures by addressing specific ecological and social aspects of the site. In the long term, the project seeks a storage volume in the range of millions of cubic meters. Furthermore, the research initiative supports Austria’s technological leadership in underground large-scale water heat storage systems in urban areas.

ScaleUp represents a research project for innovative underground tank storage designs, which will then be realized as part of a pilot storage facility. Before actual implementation, questions regarding water law regulations, system integration into the local district heating network, as well as constructional and material-related aspects must be clarified. These issues are addressed during the detailed planning phase, in which quality assurance measures are also developed that can be applied to future storage projects. To test the developed technology, a pilot project of an underground large-scale water heat storage tank with a volume of around 40,000 m³ will be constructed in the 22nd district of Vienna. This storage facility will be coupled with large heat pumps to maximize the utilization of the energy storage, increase operational flexibility, and raise the share of renewable energy in the district heating network.